Building Harlequin’s Moon by Larry Niven, Brenda Cooper

absently with her thumb, wondering what it was.
    The ground shook, almost enough to unbalance Rachel. Small rocks skittered around her ankles and she looked at the crater wall above her nervously.
    Gloria was a hundred yards ahead, clambering over rocks. She tottered, calling “Rachel!” then gave a thin cry and dropped from view.
    Rachel ran toward where she had last seen her.
    She heard noise, muffled, maybe almost a scream. She forced herself to slow down. The crater was still and silent again, the quake over. Rachel inched forward, her heart pounding. As light as Gloria was, Rachel could make out her footprints, becoming more distinct until they dropped down and out of sight. The sandy soil fell away into a fissure.
    “Gloria!” she called.
    A sound floated up to her—not a word, but a whimper.

C HAPTER 8
W ILD W ATER
    R ACHEL SQUATTED ON the edge of the drop, inches to the right of Gloria’s dragging foot tracks, and one long dragging handprint in the dust. Rachel’s feet were on hard rock, solid, crumbling away almost immediately past her, fallingto nothing, and rising as a hard edge again just twenty feet away—with a run, she could jump to the other side.
    Water gurgled below her. This wasn’t the Hammered Sea; there was no water engineering in Erika’s Folly that Rachel knew of. A wild stream? Flowing into the crater?
    “Gloria, can you hear me?”
    “Yyy . . . yow. Yesss.”
    “Be calm. I can’t see you. You’re not far down; I can hear you pretty clearly.”
    “I . . . I fell. The quake came . . . and I lost my balance, and I . . . I just slid down. The ground went away right under my feet. Rachel . . . I’m scared. It hurts.”
    “What hurts?”
    “My . . . my ankle.” Rachel heard choking sobs.
    “Are you standing on something? Is the ground good?”
    “I’m okay, I think. There’s water, and it’s running down, and it’s rocky down here and darker. I can see, but the light is thin.”
    Thin light? “Is it a cave?”
    “I can see under where you are. I can’t tell how far it goes.”
    Rachel took a step to look, and the edge crumbled under her. She tried to slide back, failed, and fell. She was right over where Gloria had fallen! She twisted, trying to angle her fall away from the girl. A thump, and she felt something under her—long, so it must be a leg or an arm. There was a sound of pain. So she hadn’t killed her, or buried her.
    “Gloria?’
    “That hurt too.” Gloria’s voice was small.
    “Yeah, well, now we’re both down here,” Rachel said dryly, trying to make it into a joke.
    She’d landed on sand on top of rocks, Gloria’s right leg under her thigh. She pushed herself back. Gloria was holding the ankle of the leg Rachel had missed; it was at least twice its normal size.
    Some leader she was. Why hadn’t she called for help? They’d be hard to find in this hole. She should have told the others right away, but she’d gotten caught up in the moment.
Gabriel will be mad at me
. She pushed the thought away, afraid it would paralyze her.
    Climbing out the way they fell in looked impossible. They’d fallen at the edge of a wide underground riverbed. Still water puddled in the center of the rocky riverbed, and water stains showed clearly the fissure walls, high up, above her head. The walls curved above her, narrowing to the slim crack they’d fallen through. High tide would drown them.
    It was only ten feet to where Rachel had just been sitting, but it might as well have been orbit. They needed another way.
    The fissure stretched up and down the crater, stream-cut, thin, and full of jumbled rocks. Rachel stood, testing. Her limbs worked. The stream floor was clearly too narrow and uneven for a girl with a sprained ankle to walk through.
    She broadcast their problem to the others while Gloria leaned into her and moaned softly. The other four were together by the flier, above the tide line, almost twenty degrees around the crater from them. It took ten precious